The present invention relates to C-shaped retaining rings for shafts or housing bores of various machines and devices, and more particularly to C-shaped retaining rings of the concentric type made by cutting a coiled slender material of rectangular cross section.
Retaining rings are known which are fitted in grooves formed in shafts or bores of various machines and devices to support an axial thrust load against axial displacement. Among such retainings, the ones formed in an overall C-shape can be divided into two general groups: eccentric and concentric.
Usual C-shaped eccentric retaining rings are advantages over C-shaped concentric retaining rings because the former can be free of the fatal drawbacks of the latter such as stress concentration, deformation to a non-circular shape, an increased space required for installation because of such deformation, and a relatively high plastic deformation and flow deformation.
Even with C-shaped eccentric retaining rings, however, it is impossible to expect theoretically perfect circular deformation owing to dimensional and structural limitations. In fact, when installed on a precisely circular shaft or in a precisely circular bore, the ring inevitably involves substantially nonuniform stress or stress concentration although unobvious to the unaided eye.
Such retaining rings for use either on shafts or in bores would function perfectly ideally as intended without involving stress concentration or nonuniform tension if the entire periphery of the ring deflects to a precise circle when the ring is stretched open or compressed at the open portion. This requires that the stress taking place at any portion of the ring be completely equal, but to fulfil this requirement, the inside and outside diameters of the ring must be in coincidence with each other at the cutout ends of the ring; the ring would then have no width at the cutout ends. Such a ring, if any, would be extremely difficult to handle and use, while it is technically very difficult or impossible to shape the ring. Accordingly C-shaped eccentric retaining rings are usually shaped to have a predetermined width at the cutout ends. However, this structure fails to ensure the perfect functioning of the ring as described above.
C-shaped retaining rings have already been proposed which are symmetrically formed with cutouts in the inner or outer peripheral edge of the ring as disclosed in U.S. Pat. Nos. 2,131,948 and No. 2,886,382. The prior art, nevertheless, does not specify nor does it explore the correlation between the cutout in the peripheral edge and the remaining width of the ring where the cutout is formed. Thus the proposed prior art rings still remain to be improved to perfect their functioning.